An embedded system is a special-purpose system in which the computer is encapsulated by the device it controls. Devices that utilize embedded systems may include, for example, information appliances, smart phones, set-top boxes, personal digital assistants (PDAs), etc.
Embedded systems often utilize the Linux operating system because it is available as open source software. Linux was initially designed for use with enterprise computer systems that have a large amount of storage space available. Embedded systems, in contrast, have a limited amount of storage space. In addition, an embedded system, unlike a general-purpose computer such as a personal computer, usually performs a single predefined function having very specific requirements. Hence, in view of space constraints and cost savings, an embedded system should provide only the storage space that is required for the specified function.
When developing an embedded system, a designer typically uses a development environment on a host PC. In particular, the developer selects a set of software packages for the embedded system and copies these software packages to the host PC. The software packages may be in the RPM (Red Hat® Package Manager) format, which is a native packaging format of the Linux operating system. The software packages are integrated into a root file system, which is then compressed to an image file and loaded to a target device. Since the target device is limited in storage volume, the developer may need to remove the unnecessary packages from the root file system in an effort to decrease the usage volume of the memory. This removal is a manual process, which is inefficient and prone to mistakes.